Semi-silica bricks compared to silica bricks have
Semi-silica bricks compared to silica bricks have
Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for __________ bricks.
Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for __________ bricks.
Magnesite bricks have poor resistance to attack by __________ slag.
Magnesite bricks have poor resistance to attack by __________ slag.
Silica refractories are not used in
Silica refractories are not used in
Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as __________ percent.
Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as __________ percent.
With increase in the alumina content in firebricks, its fusion point (refractoriness)
With increase in the alumina content in firebricks, its fusion point (refractoriness)
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.
Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.
Bauxite calcining rotary kilns are lined with __________ bricks.
Bauxite calcining rotary kilns are lined with __________ bricks.
Thermal diffusivity of a refractory brick is high, when its __________ is high.
Thermal diffusivity of a refractory brick is high, when its __________ is high.
Fusion point of an acidic refractory material is
Fusion point of an acidic refractory material is
Which is required in an insulating refractory?
Which is required in an insulating refractory?
Maximum alumina content in high alumina refractory can be as high as __________ percent.
Maximum alumina content in high alumina refractory can be as high as __________ percent.
Magnesite chrome bricks are used in the
Magnesite chrome bricks are used in the
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be
Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be
Basic bricks are not made of
Basic bricks are not made of
Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.
Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.
Highest melting (m.p = 3070°C) oxide refractory is
Highest melting (m.p = 3070°C) oxide refractory is
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm² . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm² .
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm² . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm² .
Hollow refractory bricks are made by
Hollow refractory bricks are made by
Which of the following bricks has the most close values of RUL and PCE?
Which of the following bricks has the most close values of RUL and PCE?
An ideal refractory should have high
An ideal refractory should have high
Colour of fireclay bricks is
Colour of fireclay bricks is
Which property of refractories is the most important for top section of the blast furnace?
Which property of refractories is the most important for top section of the blast furnace?
Hot metal runner in blast furnace are lined with __________ bricks.
Hot metal runner in blast furnace are lined with __________ bricks.
Silica bricks are never used for lining the
Silica bricks are never used for lining the
Fusion point of a basic refractory material is
Fusion point of a basic refractory material is
__________ bricks are used in the burning zone of a cement rotary kiln.
__________ bricks are used in the burning zone of a cement rotary kiln.
Vacuum steel degassing units are lined with
Vacuum steel degassing units are lined with
Conversion of silica mineral to cristobalite is accompanied by reduction in its
Conversion of silica mineral to cristobalite is accompanied by reduction in its
Alumina-graphite bricks are used for lining the
Alumina-graphite bricks are used for lining the
__________ bricks should not be used in oxidising atmosphere.
__________ bricks should not be used in oxidising atmosphere.
Which is the stable form of silica below 870°C ?
Which is the stable form of silica below 870°C ?
Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the
Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the
Chrome magnesite bricks are
Chrome magnesite bricks are
Which is the stable form of silica upto 1470°C ?
Which is the stable form of silica upto 1470°C ?
Which is not a natural insulating material?
Which is not a natural insulating material?
PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.
PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.
Spalling resistance of a refractory can not be increased by
Spalling resistance of a refractory can not be increased by
Chemically, mullite refractories is
Chemically, mullite refractories is
High thermal conductivity of a refractory material is not important, when it is to be used in the
High thermal conductivity of a refractory material is not important, when it is to be used in the
Mixing of ground refractory material and water is done in a __________ mill.
Mixing of ground refractory material and water is done in a __________ mill.
Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory
Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory
Porosity of fireclay refractories is __________ percent.
Porosity of fireclay refractories is __________ percent.
Carbon bricks are not used in the lining of the
Carbon bricks are not used in the lining of the
Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.
Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.
__________ is not a single oxiderefractory.
__________ is not a single oxiderefractory.
In panel test for spalling resistance, the average face temperature of panel assembly is maintained at __________ °C for 24 hours.
In panel test for spalling resistance, the average face temperature of panel assembly is maintained at __________ °C for 24 hours.
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
__________ is the measure of the strength of refractory under the combined effect of temperature & load.
__________ is the measure of the strength of refractory under the combined effect of temperature & load.
Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the
Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the
Which of the following is not a neutral refractory?
Which of the following is not a neutral refractory?
Magnesite refractories have low resistance to
Magnesite refractories have low resistance to
Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material?
Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material?
Roof of a basic electric furnace is made of __________ bricks.
Roof of a basic electric furnace is made of __________ bricks.
Addition of zircon to silica refractory brick improves its
Addition of zircon to silica refractory brick improves its
Which is not a basic refractory?
Which is not a basic refractory?
Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as __________ percent.
Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as __________ percent.
Rotary kilns meant for calcination of limestone are lined with chrome magnesite in __________ zone.
Rotary kilns meant for calcination of limestone are lined with chrome magnesite in __________ zone.
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?
Lower part of hot metal mixer are lined with __________ bricks.
Lower part of hot metal mixer are lined with __________ bricks.
Roof of a basic open hearth furnace is lined with __________ bricks.
Roof of a basic open hearth furnace is lined with __________ bricks.
Maximum safe working temperature for fireclay bricks is about __________ °C.
Maximum safe working temperature for fireclay bricks is about __________ °C.
Thermal spalling mainly occurs during __________ of furnaces.
Thermal spalling mainly occurs during __________ of furnaces.
Which brick undergoes maximum shrinkage on drying?
Which brick undergoes maximum shrinkage on drying?
Carbon refractory blocks
Carbon refractory blocks
Periclase refractory contains mainly
Periclase refractory contains mainly
Fireclay bricks is not used for lining the
Fireclay bricks is not used for lining the
Magnesite refractories are generally not used in the
Magnesite refractories are generally not used in the
Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity).
Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity).
Thermal conductivity of refractory bricks
Thermal conductivity of refractory bricks
Hot face insulating linings of high purity alumina fused mullite are used, where
Hot face insulating linings of high purity alumina fused mullite are used, where
Hot blast main (carrying air at 1000°C) in blast furnace are lined with __________ bricks.
Hot blast main (carrying air at 1000°C) in blast furnace are lined with __________ bricks.
Cold crushing strength of a refractory does not depend upon its
Cold crushing strength of a refractory does not depend upon its
Insulating refractories should have
Insulating refractories should have
Chromite refractories are
Chromite refractories are
Outer combustion chamber of blast furnace stove is lined with __________ bricks.
Outer combustion chamber of blast furnace stove is lined with __________ bricks.
Zirconia refractories are not used in
Zirconia refractories are not used in
High alumina refractories are used in the
High alumina refractories are used in the
An indication of degree of firing in silica brick is its
An indication of degree of firing in silica brick is its
Cold crushing strength of refractories depends upon its
Cold crushing strength of refractories depends upon its
Permeability of bricks is a measure of the
Permeability of bricks is a measure of the
Which one contains maximum percentage of Al2O₃ ?
Which one contains maximum percentage of Al2O₃ ?
Which is not an acidic refractory?
Which is not an acidic refractory?
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of
Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
Firing temperature of magnesite bricks is about __________ °C.
Firing temperature of magnesite bricks is about __________ °C.
Maximum water percentage in refractory mix meant for hand moulding may be as high as __________ percent.
Maximum water percentage in refractory mix meant for hand moulding may be as high as __________ percent.
Which of the following is not an acidic refractory?
Which of the following is not an acidic refractory?
Porosity of silica bricks varies from __________ percent.
Porosity of silica bricks varies from __________ percent.
Carbon refractories
Carbon refractories
Which is the stable form of silica between 1470°C and the melting point 1713°C ?
Which is the stable form of silica between 1470°C and the melting point 1713°C ?
Presence of MgO in alumino-silicate refractories __________ its refractoriness.
Presence of MgO in alumino-silicate refractories __________ its refractoriness.
Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks.
Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks.
Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.
Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.
Which of the following is not a high alumina refractory material?
Which of the following is not a high alumina refractory material?
Test piece for determination of RUL of a refractory is heated in a/an
Test piece for determination of RUL of a refractory is heated in a/an
Refractory bricks having lower porosity have
Refractory bricks having lower porosity have
